Flying-wing aeroplane



Ma ch 24, 1931. w, w, CHRISTMA; 1,797,326 FLYING WING AEROPLANE Filed July 18, 1929 2 SheQts -Shee l March 24, 1931. w. w. CHRISTMAS FLYING WING AEROPLANE Filed July 18. 1929 v 2 Sheats-Sheet 2 Patented Mar. 24, I931 UNITED STATES.

WILLIAM WHITNEY CHRISTMAS, OF NEW YORK; N. Y-, ASSIGNOR, BY, MESNE ASSIGN- MENTS, TO THE GENERAL DEVELOPMENT COMPANY, OF HARTFORD, CONNECTICUT,

A CORPORATION OF CONNECTICUT FLYING-WING AEROPLANE Application filedl'uly 18, 1929. Serial No. 379,269.

My invention relates to the art of aviation and it'has for its objectthe improvement of aeroplanes with respect to carrying capacity, reliability ofoperation, speed, convenience and safety. My present invention is closely related to the invention described and claimed inmy prior copending application, Serial No. 374,449, filed June 28, 1929. In that application I have described and illustratedan aeroplane in the ormof what I call a flying wing, of such form and dimensions as to enable passengers, freight, and other material to be carried within or upon the body of the wing as such, witlgut any fuselage. In that application howe r I have given no details, and t epurpose the present application is to evelop certain details of construction and rrangement of my "flying wing with particular reference to the comfort and convenience of passengers, the

handling and storing of mail, the accommodation of express and otheilfl matter, the proper balancing of all these asseswith respect to the center of pressure for stabilizing purposes, and certain other fiaatures which will sufiiciently appear from t e detailed description hereinafter. Very "briefly stated,

"my present invention comprises a multiple unit hollow wing structure composing as a whole a cantilever truss. This consists of two outer truss sections correspbnding to the usual wings of an aeroplane ponnected by aficentral section forming a cotinuous part of the aerofoil structure(0f mnoplane design), and performing also th important function of receiving and car 12' itself the greater part of the load .of the plane. Extending fore and aft across'the main truss frame, built into the truss and" 40. projecting therefrom, are a pair of parallel outriggers of truss construction which at their rear endscarry .the stabilizer, elevator, and rudders, constituting the tail group, and at their front ends carry the propellers, projecting from the leading edge of the wing. The propeller shafts extend axially through the outrigger trusses, and within the same the motors are,preferab ly, mounted, so as. to be able to couple any desired number of units above, below or on each side to each shaft.

ng within divided b The pilot house containing the controls is located either beneath or above this same centralsection, and access thereto is either throu h the floor or ceiling as the case may be. rdinarily the pilot will be separated froin the engineer by about 25 ft. and will communicate with him by signals; but my present. arrangement follows the best sea pilot house practice. By the foregoing arrangement personal communication and complete control ofthe ship are rendered possible, which before were impossible. In fact, it will be observed'from the descri tion and illustration herein that I have fo lowed as closely as possible the practice both in design and operation, includmg the signal system, which is followed on ocean going steamships, or other motor craft. The underlying purpose of my design is to secure stability, reliability, efliciency, and safety, since these elements are absolutely essential to continuous and uninterrupted commercial operation.

The entire'wing' structure as at present de signed, is composed of a multiplicity of frame units, each unit transversely and otherwise braced in intersecting planes both fore and aft and ath'wartshi may be composed 0 steel tubes or the equiva- The individual units lent, united by union or other cou lings or other suitable connecting means, t es'e couplings also preferably carrying the anchor age lates for clevises forming terminals for this1 diagonal braces or suspension cables or ro s.

The interior of the central section is thus the unit arrangement and the diagonal races into cubical spaces 20f ap-.

proximately 7 ft.on a side. It wi understood that this figure may be varied according to proper engineering design which i in turn will-follow the best engineering prac-' tice for frames of this type. t will noted that the center of pressure (or center of effort as otherwise known), in this flying wing is located approximately one third of the length of the chord aft of the leading edge. The two side wing extensions are so constructed and arranged as to form a dihedral angle, both upper and lower surfaces, and the entire plane is balanced with respect to the center of efi'ort or pressure. In order to attain this, and to enable the tail group to be properly set and adjusted, the weights to be carried in the center compartment and in the adjacent wings, will be accurately determined and located. 1

One important purpose of the present invention therefore is to so plan this center compartment as to secure the greatest comfort and convenience for the passengers, and the largest available space for carrying freight and other necessary load, which are compatible with a proper balance. I attain this object by locating the massed passenger-s seats preferably in parallel rows and as many rows deep as may be required, near the front of the section, and by arranging all ancillary space such as lavatory, lounging room, smoking room, dining room, cabins, express, mail and radio rooms, the captains and crews quarters and such other accommodations as may be required according to the best ship practice, around the sides and across the rear of the passengers seating space. The motors are on both sides parallel and of equal numbers ofunits, so that they balance. On the outsides of the respective parallel Outriggers, and housed within the wing structures are facilities for carrying and for handling express and mail matter, together with bulk storage spaces for freight.

Other features will sufficiently appear from the description hereinafter.

My invention is illustrated in the accompanying drawings, in which- Fig. 1 is a diagrammatic view on a reduced scale of the ship as a whole.

Fig. 2 is a side view of the same.

Fig. 3 is a front view of the same.

Fig. 4 is a diagrammatic plan view on an enlarged scale showing the engines, the driv-- ing shafts and propellers, and the details and furnishings of the central section of the ship.

In reading this description, it should be borne in mind that the primary underlying purpose of the entire design is to produce a practical commercial type of ship that may be profitably employed in the carrying trade. The smaller type of aeroplane heretofore produced is impracticable and inoperative for sustained commercial purposes. Small units, even in sufficient numbers to satisfy the recompete with large self-contained and-efiicient units which again agrees with the general law of commercial carriers. For exam- .ple, the ship herein described is designed to carry as much as 30 of the ordinary aeroplanes heretofore employed. Where each of these 30 would have two pilots per ship the present ship has but two pilots. Where the ordinary ships in commercial use would have crews averaging3 per ship, or a total of 90 for the 30 ships, the present ship has a crew of approximately 11. In all other respects such as insurance, deterioration charges, replacement, etc., as well as general upkeep, there is a very great saving in the use of the large unit. It will be apparent therefore that there is something more than convenience and accommodation of the needs or wishes of the public, in the increase of size and carrying capacity, and applicant believes that he is the first to conceive and present a practicable design and arrangement for this purpose, and he will claim the same herein accordingly.

It will be understood that while the disposition and arrangement herein described are considered by applicant to embody the best method of practicing his invention now known to him, nevertheless he is aware that numerous changes may be made in matters of detail, and gives notice that he considers the same to be included in and covered by the claims hereunto appended. For example, instead of having one central section containing the passengers seats, the dining salon, etc., there may be more than one; and instead of having two Outriggers or supporting trusses for the tail group, the motors, and the propellers, there may be one, two or three or more of these. If there be any odd numbers of these outrigger trusses, then of course there would have to be an even number, that is to say, two, four or more of the carrying sec,- tions referred to as the central section. The necessity for balancing and stabilizing must never be lost sight of, although within limits masses relatively small with respect to the entire burden carried, may be shifted around without loss of stability. Thus, passengers may leave their seats and move about, and the crew may do the same in the performance of their duties without noticeably afi'ecting the balance or stability of the plane as a whole. In this respect a large ship of this type can show itself superior to smaller units, and compares favorably with water ships. In either case simultaneous mass movements of the live load in the same direction are not expected, but even these, unless a vessel as designed is crank would not have any dangerous effect.

In addition to this central section having sufficient head room for persons within itself, the adjacent section or sections in the wing as shown in the drawings may also have head qulrements of the trade, cannot compare or extending from one tip a to the other tip a. The central portion a of this wing has the leading edge and the trailing edge parallel or substantially so. The extended portions of the wing truss on the other hand, are referably tapered as shown in Fig. 1, the ront or entering edge being not only somewhat I oblique but also rounded off at u while the rear or trailing edge is somewhat more oblique with each aileron extended for approximately two-thirds of the distance from the tip to the base-of the wing truss. It will be understood that these dimensions are abitrary and may be varied without departing from the invention. The two wing trusses .a--a are so built and proportioned as to form a dihedral angle, with the central portion a extending in a common plane between them. The usual spars, which may be com.- posed of trusses, girders or beams, extend from tip to tip of the wing as indicated at a a. Extending fore and aft, parallel with each other, and crossing the main aerofoil or truss, are two outriggers 0-0. The structure of these and of the main truss A will be presently described more in detail, but at this point it is only necessary to say that the outriggers are in box form and at their rear ends carry the" tail group T including stabilizer truss T, elevator E, and rudders RR'R In order to prevent warping or longitudinal vibration of these parts, a pair of diagonal cables CC' are secured from points c0 to the point a so as to stiffen the entire structure.

It is not intended in the present application, as-it forms no direct part of the present invention, to describe the detailed mechanical structure of the main wing or aerofoil and the Outriggers. It should be stated however that both are built of assembled units of tubing which may be for example chrome molybdenum steel, varying in diameter from 3 to 5 inches for the larger parts and down to inch for the smallest parts. These tubes are made in standard sections, are assembled by means of couplings to form a reticulated frame uniform in every direction and cross braceddiagonally of the truss in both horizontal and vertical planes.

The present design is not intended for small ships, the appropriatedimensions of a standard unit being as follows:

Span over all from tip a to a is 230 feet.

feet.

Depth of chord wing tips a-a' is 25 feet. Center section a is 40 feet by 55 feet. Outriggers 0-0 in box form are 7 ft. :2: 7 ft. in wider section, tapering to 5 ft. w-2 ft. at the tail group, and 3 ft. :1; 3 ft. at each propeller.

middle section a (see Fig. 2) is 28 ft.

Depth of chord, middle section a is 55 Height of plane from ground to underside of middle section a is 20 ft. 9 in.

Height of plane at wing tips aa' is 35 ft.

The tail group T, with the exception of the truss T, which is built and assembled similarly to the body of the aerofoil and the outrigger-s, are of known or any suitable construction and are operated by controls worked in any suitable manner. but preferably by means of a hand wheel W moving the elevator. in its ({force and aft motion, the ailerons in its si e motion, and the rudders in its rotary motion. The wheel W is located in the pilots control station which may be lo cated on the central section a of the plane either above or below or within the same, or in any other position suitable to the piloting and navigation of the ship.

A characteristic feature of this plane hes in the supports S-S' for the landing gear connected at L-L'. These supports SS are of any suitable material, including metal and wood, forming boxes or tanks which from their dimensions and location are well adapted to carry quantities of fuel or other material to be transported, or the pilot or pilots. The upper part of each of these supports S-S is built into the structure of one of the Outriggers OO',' as indicated in Figs. 2 and 3.

Between the two outrigger'bodies O()' the central portion of the main wing truss a is designed to house and carry passengers, freight, and supplies, except fuel. The motors MM-M are enclosed in the space within the outrigger bodies where they cross the main truss.v Two of these motors point forwardly and one points to the rear, with a master gear between them meshing with pinions or gears on the respective motor shafts, which may be thrown into and out of engagement atwill by the engineer. For this being connected to the master gear, so that it may receive power from 1, 2 or 3 engines at will. In the machine described, the propellers have a diameter of 30 feet and operate at a maximum speed of 400 R. P. M.

The front or leading edge of the central section a. is provided with windowsof nonshatterable glass in metal frames, as indicated at G in Figs. 1 and 2. The upper part of the entering edge is preferably solid, in common with the rest of the surface of the wing or aerofoil, which is adapted to resist all weather conditions, a suitable covering for this purpose being for example, veneered wood sheathing covered withstainless steel. The vertical dimensions between the upper and lower surface of the central section a Height of plane from ground to top of ofthe wing'being approximately 7- ft. 6 in.

and the area of this central section being approximately 2100 sq. ft. there is ample space and head room for the location of seats for approximately 55 passengers, with rest rooms, dining room, smoking rooms, cabins, and other conveniences customary on cruising ships. The glass Windows G in their metal frames, afford a clear view at all times for the passengers and the weight is where it should be, to stabilize the plane.

Referring now to Fig. 4, this is a fragmentary diagrammatic figure showing the central section a of the aeroplane and particularly the equipment and furnishings thereof in detail, together with the two outrigger structures O() and the adjacent portions of the outer wing sections a*a In this figure, the sectional unit structure with its tubes and diagonal braces or eantilever members, is omitted for clarity. but it will be understood that the seats in the passenger section, the tables in the salon, and the furniture and fittings in the other rooms are disclosed with proper reference to these unit sections. With this understanding, the floor plan of the section a shows the outer wall composed of windows G which as heretofore described are in the leading edge of the plane wing; and a partition a with doors (L -a opening from aisles a between which are arranged the passengers seats in rows of seven, four rows on each side. It has already been stated that the ship would accommodate approximately 55 passengers. There are 56 seats shown but of course this number is arbitrary and can be varied within limits, being assumed for a ship of the dimensions hereinto given, which in addition to the live load will carry a certain amount of dead load in the shape of freight, mail and express matter, baggage, and stores. The amount of stores is reduced however by the fact that the present design is not intended for long voyages, such as. those across the ocean, but is particularly adapted to land service between points which may be from 1,000 to 1,500 miles apart; or for transcontinental voyages with one or two stops for refueling, which of course would give an opportunity for renewing stores. Such a design as this is well adapted for example for regular commercial service between New York and Chicago, which would involve about a six hour run.

The forward apartment a thus described may be called the observation salon, since the passengers at all times have a clear view ahead and downwardly, as it will be observed in Fig. 2 that the windows G are in the lower portion of the leading edge; Thepassengers seats may he stepped up from the first to the last row to give clear vision.

Abaft of the partition or bulkhead a is the main dining salon D, containing tables (l each centered within one sectional division of the cantilever construction. On each side of this dining salon is located a kitchen K which in addition to cooking and refrigerating equipment may contain a hot table for con venience. Immediately abaft each kitchen is a writing room F, a lavatory H, and telephone room I. These rooms all being in pairs, the weight of equipment is balanced and the amount of equipment required in each one is reduced. Across the rear of the' dining salon are lounges J-J for ladies and men, quarters N-N for the captain and crew and a radio room Q. These again are balanced, and the weight of equipment also balanced. Moreover, it will be noticed that the fore and aft series of rooms K, F, H and I on each side are included in the truss frame or structure of an outrigger 0, thus by the weight of their equipment balancing 'the weight of the motors MMM in the fore part of the truss structure.

Outside of the two outrigger structures 0, I arrange racks U to support mail bags, over which may also be arranged sets of pigeon holes or shelves if desired, for the purpose of sorting or working the mail during a run. It will be noted that the weight of these mail bags and their contents is also divided and equally distributed on both sides of the center of pressure, and that the air mail clerks who handle this matter occupy the space between the upper and lower faces of the outer wing member or trusses a a The spaces a a in the wing trusses outside of the outriggers O are therefore provided with head room and afford sufficient space not only for the mail bags but for general freight, express and baggage. All of this matter is obviously divided and balanced as before.

The operation of the motors has been briefly referred to, and while not directly a part of the present invention, it may be pointed out that the dimensions of the truss members OO are such as to afford a comfortable and commodious engine room with ample space for the motors and side spaces for the engineer to gain access to the individual motors MMM the several clutches or coupling means, the master gear M andthe main shaft P. In fact, the engineer has access to every part of the machinery up to the forward'shaft hearing, at p, which will be a heavy frictionless bearing equipped with rollers or other means requiring little attention on short runs.

I have indicated in dotted lines in Fig. 4 girders or frames V for supporting the passengers seats, or'the equivalent repositories for freight or other matters of cargo. This arrangement of girders constitutes the solution of a problem having a serious bearing on the construction and successful operation of the machine. The center of gravity of an aeroplane should be at a point about 28% of the wing chord from the leading edge. Therefore, the centers of gravity of the loaded ship and of the empty ship should beso arranged as to" bring the combined center of It is also desirable movements of all individual passengers, but

it is possible to control mass movements and toso arrange the load,will voluntari y assume in general so that said load will alter the center of gravity if necessary, or will maintain the same if al-' ready properly fixed, to or 'at the correct point indicated. Eor this purpose, in the present case the rows of passengers seats are located in the center section a at the front thereof, and the means for securing the passengers presence in these seats are the observation o enings Gr. It will be understood that by t is massing the load, at the front or leading edge, the center of gravity is fixed at 'lt)hel({les1red point if necessary it can be moved ac v The cruisin speed of this machine is from to 130 mi es per hour, and its landing speed is approximately 41 miles per hour, the landing being rendered safe and easy by the large wing area and the relative close approach of the entire area to the earth, which produces air compression with consequent ra id deceleration.

a at I claim is:

1. In an aeroplane, a single continuous wing or aerofoil of the type described without any central fuselage or equivalent enlargement but with a central section having suflicient head room within itself to accommodate persons, at series of supporting girders in said section extending from side to side thereof in the bottom of the lane adjacent to the leading edge thereof, 0 servation openings in said leading edge, and seats for passengers within said section supported upon said g1rders to mass the weig t of the passengers in sucli relation to the weight of the unloaded ship as to maintain the center of gravity in its proper relation to the leading e observation openings being so locate in the leading edge as to be available to the passengers for observation urposes only when their weight is located an massed to properly adjust the center of gravity, as described herein.

2. In an aeroplane, a single continuous wing or aerofoil of the described, having suflicient head room wit itself to accom- Y modate persons, and window li hts or open ingS in said wing, with frames uilt into the structure of the wing to support said persons said frames and said windows being so loca with respect to each other a nd to the center of gravity that the windows will be available only when the persons are properly located to" ositions which the live express and such other matter as is usuall transported in or on commercial carriers, a l symmetrically arranged for stabilizing with respect to the normal mass location of passengers.

4. An aeroplaneas described in claim 1, having side sections adjacent to the central section also provided with suflicient head room within themselves to accommodate persons and cargo, and having supporting floors symmetrically arranged with respect to the main support for passengers so as not to measurably affect the center of gravit 5. An aeroplane of the type descrlbed in claim 1, havin a central portion or portions of thewwing divided and framed to receive and carry massed passengers, supporting means, and auxiliary supply means and conveniences for the passengers located in a symmetrical figure with respect to said passengers and supporting means around the center of gravity.

6. The aeroplane described in claim 1, having two fore and aft outriggers built into and crossing thewing and enclosing the-central portion thereof between them, means in the rectangular structure thus produced for carrying propellers, power plant, tail group, controls, ship personnel, and passen ers and a floor structure to carry the masse weight of passengers extending parallel to the leading edge from one outrigger to the other, substantially as described. I

In testimony whereof I hereunto alfix my signature.

WHITNEY CHRISTMAS.

e, said- 

